app.py

import os, requests, gradio as gr
from huggingface_hub import InferenceClient

client = InferenceClient("meta-llama/Llama-3.3-70B-Instruct", token=os.getenv("HF_TOKEN"))

def safe_int(val, default=0):
    try:
        return int(val) if val is not None else default
    except (ValueError, TypeError):
        return default

def fetch_catalog_detailed(query, limit):
    try:
        url = f"https://openlibrary.org/search.json?q={query}&limit={limit}"
        response = requests.get(url, timeout=5)
        docs = response.json().get("docs", [])
        return [{
            "title": d.get("title", "Unknown"),
            "author": ", ".join(d.get("author_name", ["Unknown"])),
            "year": safe_int(d.get("first_publish_year"), 1000), 
            "editions": safe_int(d.get("edition_count"), 0)
        } for d in docs]
    except:
        return []

def librarian_agent(message, history, session_state, sort_by, num_results):
    # Prevent crashing if user moves slider before typing a query
    if not message or message.strip() == "":
        return history, session_state

    if session_state is None:
        session_state = {"verified": False, "age": None}

    if not session_state["verified"]:
        age_digits = "".join(filter(str.isdigit, message))
        if age_digits:
            session_state["age"] = int(age_digits)
            session_state["verified"] = True
            reply = "✅ Verified. What topic are we researching?"
        else:
            reply = "👋 Please enter your age to start."
        history.append({"role": "assistant", "content": reply})
        return history, session_state

    # Core RAG Logic
    raw_books = fetch_catalog_detailed(message, int(num_results))
    
    if sort_by == "Newest First":
        raw_books = sorted(raw_books, key=lambda x: x['year'], reverse=True)
    elif sort_by == "Popularity":
        raw_books = sorted(raw_books, key=lambda x: x['editions'], reverse=True)

    catalog_summary = "\n".join([f"BOOK: {b['title']} | YEAR: {b['year']} | EDITIONS: {b['editions']}" for b in raw_books])

    llm_messages = [
        {"role": "system", "content": f"You are a librarian. Output ONLY a Markdown table: | Book & Author | Year | Editions | Summary |."},
        {"role": "user", "content": f"Catalog:\n{catalog_summary}\n\nUser: {message}"}
    ]

    try:
        output = client.chat_completion(messages=llm_messages, max_tokens=1000)
        bot_res = output.choices[0].message.content
    except Exception as e:
        bot_res = f"Error: {str(e)}"

    history.append({"role": "user", "content": message})
    history.append({"role": "assistant", "content": bot_res})
    return history, session_state

# --- GRADIO UI ---
with gr.Blocks() as demo:
    gr.Markdown("## 📚 Fully Dynamic AI Librarian")
    state = gr.State(None)
    
    with gr.Row():
        sort_option = gr.Dropdown(["Relevance", "Newest First", "Popularity"], label="Sort", value="Relevance")
        result_count = gr.Slider(minimum=3, maximum=15, step=1, value=5, label="Results Count")
    
    chatbot = gr.Chatbot(label="Catalog", value=[{"role": "assistant", "content": "👋 Enter your **age** to begin."}])
    msg = gr.Textbox(label="Query", placeholder="Search books...")

    # Pack inputs for reuse
    inputs_list = [msg, chatbot, state, sort_option, result_count]
    outputs_list = [chatbot, state]

    # EVENT 1: Submit on Enter
    msg.submit(librarian_agent, inputs_list, outputs_list).then(lambda: "", None, msg)

    # EVENT 2: DYNAMIC REFRESH
    # When slider or dropdown changes, re-trigger the agent automatically
    result_count.change(librarian_agent, inputs_list, outputs_list)
    sort_option.change(librarian_agent, inputs_list, outputs_list)

demo.launch()